As a resin-made pipe joint which is used for a tube for a fluid (for example, high purity liquid, ultrapure water, or chemical liquid) to be handled in a production process of various technical fields such as production of semiconductor devices, production of medical equipment and medicines, food processing, and chemical industry, for example, a resin-made pipe joint disclosed in Patent Literature 1 is known.
A resin-made pipe joint of this kind includes a joint body, an inner ring (sleeve), and a press ring (fastening member). The fastening member is configured by a union nut and the like so that the member can fasten a tube to be coupled to the resin-made pipe joint, to the joint body through the sleeve.
The joint body has a body cylinder portion, an outer cylinder portion, and an inner cylinder portion. The outer cylinder portion is coaxially projected from the body cylinder portion in one axial direction. The inner cylinder portion is placed radially inside the outer cylinder portion, and coaxially projected from the body cylinder portion in the same direction as the outer cylinder portion so that a projection end is located on the side of the body cylinder portion with respect to the projection end of the outer cylinder portion.
In the joint body, a groove portion which opens in one axial direction is formed while being surrounded by the body cylinder portion, the outer cylinder portion, and the inner cylinder portion.
The sleeve has a cylindrical fitting portion, a cylindrical coupling portion, a cylindrical inserting portion, and a cylindrical restricting portion. The fitting portion is configured so as to be detachably fitted to the radially inner side of the outer cylinder portion. The coupling portion is projected from the fitting portion in one axial direction, and configured so as to be press-inserted into a one longitudinal end portion of the tube.
The inserting portion is coaxially projected from the fitting portion in the other axial direction, and configured so as to be inserted into the groove portion of the joint body from the opening portion of the groove portion.
The restricting portion is placed radially inside the inserting portion, and projected from the fitting portion in the same direction as the inserting portion so that the projection end is located on the side of the fitting portion with respect to the projection end of the inserting portion.
In the resin-made pipe joint, then, the tube is coupled to the sleeve, and thereafter the inserting portion is press-inserted into the groove portion while restricting deformational movement of the inner cylinder portion by the restricting portion, whereby the sleeve is connected to the joint body, and thereafter the tube is fastened to the joint body by using the fastening member, whereby the tube can be coupled to the resin-made pipe joint.